Interleukin-8 is a powerful prognostic predictor of all-cause and cardiovascular mortality in dialytic patients.

BACKGROUND: Cohort studies have demonstrated an association between C-reactive protein (CRP) and interleukin-6 (IL-6) and all-cause and cardiovascular mortality in end-stage renal disease (ESRD) patients. Interleukin-8 (IL-8) appears to be not only the plasma expression of the acute-phase response but also a direct pathogenetic mediator of the atherosclerotic process. METHODS: To evaluate the role of IL-8 in predicting outcome, 76 chronic dialytic patients were prospectively followed for 18 months. At baseline, blood samples were taken for analysis of high-sensitivity CRP, IL-6, IL-8 and other standard laboratory analyses. RESULTS: Median IL-8 was 5.2 mg/l, therefore near half of the patients had IL-8 values within the range of 'normal limits'. IL-6 and CRP were significantly correlated (r = 0.45, p < 0.001) and a positive correlation was also found between IL-6 and IL-8 (r = 0.39, p < 0.001). The correlation coefficient between IL-6 and CRP was 0.43 (p < 0.001) and 0.50 (p < 0.001) in patients without and with history and/or clinical signs of cardiovascular disease, respectively. After a follow-up of 1.5 years, 8 patients had died from cardiovascular causes and another 7 patients for other reasons; furthermore 9 major nonfatal cardiovascular events were recorded. Stepwise regression analysis showed IL-8 as the strongest independent predictor of all-cause and cardiovascular events (p = 0.0025) even after adjustment for age and dialytic age, followed by IL-6 and CRP (p < 0.01). CONCLUSION: Despite a small population and a relatively short follow-up period, this study firstly demonstrated that IL-8 is a powerful independent predictive factor for cardiovascular and overall mortality cause in ESRD patients.

In vivo and in vitro effects of simvastatin on inflammatory markers in pre-dialysis patients.

BACKGROUND: The beneficial effects of statins in reducing cardiovascular events have been attributed predominantly to their lipid-lowering effects, recent studies suggest that these effects might be due to their anti-inflammatory properties. We here investigate the in vivo and in vitro effects of simvastatin on cytokine production in pre-dialysis chronic renal failure patients. METHODS: Our clinical study has been designed as a randomized double-blind placebo controlled study. A total of 55 chronic kidney disease (CKD) patients at stages 3 and 4 (mean creatinine clearance 45 ml/min, range 15-60) were randomly assigned to receive simvastatin 40 mg/day or placebo, added to their ongoing treatment, for 6 months. Blood samples were obtained at baseline, and after 3 and 6 months of observation for the determination of lipids, inflammatory markers and renal function. For the in vitro studies, the effect of increasing doses of simvastatin on cytokine production [namely interleukin (IL)-6 and IL-8] in human cultured monocytes from 10 healthy subjects (HS) and 15 CKD patients stimulated by lipopolysaccharide (LPS) was investigated. RESULTS: A significant reduction in total cholesterol from 221+/-44 mg/dl to 184+/-41 mg/dl (3 months) and to 186+/-39 mg/dl (6 months) (P<0.02) and low-density lipoprotein cholesterol from 139+/-40 mg/dl to 104+/-29 mg/dl (3 months) and to 100+/-31 mg/dl (6 months) (P<0.001) was observed in the 28 patients treated with simvastatin. In this group, C-reactive protein (CRP) levels significantly decreased from 2.6 mg/l [interquartile range (IQR 4.9)] to 2.0 mg/l (IQR 1.9) (P = 0.03) at 6 months (P<0.05). A parallel reduction of IL-6 levels from 5.1 pg/ml (IQR 3.8) to 3.5 pg/ml (IQR 3.1) (P = 0.001) at 6 months was also observed. No significant reduction in inflammatory markers [CRP from 5.1 mg/l (IQR 1.9) to 5.4 mg/l (IQR 1.3) (P = NS) at 6 months] or plasma lipids [LDL-cholesterol from 127+/-32 mg/dl to 131+/-21 mg/dl (6 months)] was observed in the 27 patients of the placebo group. In the in vitro studies, the average value for cell-associated IL-6 and IL-8 was higher in CKD (155+/-95 pg/ml monocytes for IL-6 and 722+/-921 pg/ml monocytes for IL-8) vs HS (137+/-87 pg/ml monocytes and 186+/-125 pg/ml monocytes) (P<0.01) and was not affected by simvastatin alone. LPS resulted in a significant increase in cytokine production (IL-6: 1954+/-321 pg/ml monocytes for CKD and 1451+/-237 pg/ml monocytes for HS; P<0.001); the simultaneous addition of increasing doses of simvastatin to these cultures induced a dose-dependent inhibition of IL-6 and IL-8 production in stimulated peripheral blood mononuclear cells in all groups. CONCLUSIONS: These results indicate that simvastatin in commonly used doses has an in vitro and in vivo anti-inflammatory effect in CKD patients, and may play an important role in counteracting the mechanisms involved on the pathogenesis of cardiovascular disease.

Effects on inflammatory and nutritional markers of haemodiafiltration with online regeneration of ultrafiltrate (HFR) vs online haemodiafiltration: a cross-over randomized multicentre trial.

BACKGROUND: HFR [double chamber haemodiafiltration (HDF) with reinfusion of regenerated ultrafiltrate] is a novel dialytic method which combines the processes of diffusion, convection and adsorbance. In this technique an adsorbent cartridge of resin and charcoal may regenerate the ultrafiltrate suggesting its use as an endogenous substitution fluid. The aim of this multicentre randomized cross-over study was to compare HFR to online HDF in terms of inflammatory and nutritional parameters. METHODS: After a 1 month run-in period of standard bicarbonate dialysis (HD) with a synthetic membrane, 25 chronic dialytic patients were randomized (A-B or B-A) to be treated by HFR (A) with a two-chamber filter (SG 8 Plus - high permeability Polysulphone HF 0.7 m2 + SMC 1.95 sqm; Bellco, Mirandola, Italy) or by online sterile bicarbonate HDF. Each study period of 4 months was separated by 1 month of HD and the entire length of the study was 10 months. CRP levels were measured by a highly sensitive nephelometric assay (Dade, Behring) with a sensitivity of 0.1 microg/ml. Cytokine concentrations were determined by EIA [Interleukin (IL) 6, Biosource, USA and IL-10 Bender MED-Systems, Vienna]. The sensitivity thresholds were < 5 pg/ml for IL-6 and < 8 pg/ml for IL-10. Serum leptin was determined with a ELISA method (Biosource, USA). All parameters were determined monthly in patients starting a midweek dialytic session. RESULTS: Plasma CRP and IL-6 were significantly reduced during the 4 months of HFR and HDF: CRP from 8.0 +/- 3.2 to 5.6 +/- 3.4 mg/l with HFR (P < 0.05) and from 9.4 +/- 4.3 to 5.9 +/- 3.9 mg/l with HDF (P < 0.05). IL-6 decreased from 14.8 +/- 6.3 to 10.1 +/- 3.2 with HFR (P < 0.02) and from 12.1 +/- 4.2 to 9.6 +/- 3.7 with HDF (P = ns) with a percentage decrease after 4 months of 32% with HFR vs 21% with HDF. During the 1 month wash-out period with HD, CRP increased from 5.7 +/- 3.6 to 8.7 +/- 3.9 mg/l (P < 0.01) and IL-6 from 10 +/- 3.4 to 13.5 +/- 5.2 pg/ml (P < 0.01). A significant increase in IL-10 was detected either in HFR (from 4.8 +/- 2.1 to 6.89 +/- 1.7 pg/ml) and in HDF (from 3.3 +/- 1.7 to 8.95 +/- 4.3 pg/ml; P < 0.05) after 4 months. No significant variation in serum leptin levels were observed during the study. CRP and IL-6 were highly correlated (r = 0.54; P < 0.001) as was serum albumin and prealbumin (r = 0.39; P < 0.001). Serum albumin was negatively correlated with CRP (r = -0.26; P < 0.01) and IL-6 (r = -0.19; P < 0.05); serum prealbumin was correlated with IL-6 (r = 0.37; P < 0.001) and with CRP (r = 0.24; P < 0.01). CONCLUSIONS: Haemodiafiltration with online regeneration of ultrafiltrate and online HDF are highly biocompatible techniques and no significant difference between HFR and online HDF was observed in terms of reduction of inflammatory markers. Further studies with a longer follow-up are needed to evaluate the clinical relevance of the online endogenous reinfusion to counteract the chronic inflammatory state of the uraemic patient.

Ceruloplasmin and acute phase protein levels are associated with cardiovascular disease in chronic dialysis patients.

BACKGROUND: The most frequent cause of death in hemodialysis (HD) patients is cardiovascular disease (CVD), and chronic inflammation has been identified as an epidemiologically important risk factor for CVD. Elevated levels of minor acute phase reactants, such as ceruloplasmin (Cp) and transferrin, have been related to an increased cardiovascular risk in the general population, but little information is available regarding dialysis patients. We investigated the correlation between Cp and copper concentration (Cu) with major acute phase reactants such as C-reactive protein (CRP) and interleukin-6 (IL-6) in a population of chronic dialytic patients. Furthermore, we evaluated the relationship between long-lasting acute phase proteins such as Cp and nutritional markers. PATIENTS AND METHODS: CRP (Berhing Diagnostic, high sensitivity modified nephelometric technique, detection limit 0.1 mcg/mL), IL-6 (EIA, RD Systems), serum albumin, prealbumin, Cp (Berhing, nephelometric assay), copper (mass spectrometry, Varian) and standard laboratory routine analysis were determined in 75 stable chronic dialysis patients (age 60 +/- 16 yrs; dialytic age 65 +/- 50 months ) starting a midweek dialytic session. RESULTS: Thirty-seven patients (49%) had clinical signs of cerebrovascular, cardiovascular or peripheral vascular disease. Fifty-one patients (67%) showed biochemical inflammation markers as suggested by elevated CRP levels (mean 12.4 mg/L, SD 11.5) and IL-6 (mean 21.3 pg/mL, SD 19.7) with a positive correlation (r=0.65; p<0.001) between CRP and IL-6. CRP and IL-6 also related negatively to nutritional markers such as albumin and prealbumin (r=-0.42; p<0.01). Cp related significantly to CRP (r=0.4; p<0.001) and IL-6 (r=0.41; p<0.001), and as expected to copper (r=0.96; p<0.001), but not with serum albumin and prealbumin. In a multivariate logistic regression analysis, age (p<0.001), dialytic age (p>0.01), IL-6 (p=0.04) and Cp (p=0.02) were the strongest risk factors for cardio-vascular disease (CVD). CONCLUSION: These data suggest that serum Cp could be useful in monitoring the ""chronic inflamed"" patient and support the suggestion that elevated metalloprotein levels are associated with an increased cardiovascular risk in a population of stable dialysis patients.

Severe hypotension during hemofiltration in an uremic patient with metabolic alkalosis.

We describe a case of medication induced metabolic alkalosis in a maintenance dialysis patient who developed severe hypotension while undergoing a lactate hemofiltration procedure. A 73-year-old man with ESRD due to renovascular disease was used to ingesting up to 30 grams per day of a non-prescription medication (Effervescent granulare 250 grams, CRASTAN, Pisa Italy) consisting of sodium bicarbonate, citric acid, glucose and lemon flavor. For technical problem lactate hemofiltration was performed and thirty minutes after dialysis was started a severe symptomatic hypotension occurred (blood pressure 65/35 mmHg). Lactate hemofiltration was suspended and one-hour later standard bicarbonate dialysis was performed without any clinical problem. The different mechanisms in acidosis buffering occurring in lactate and bicarbonate hemofiltration were discussed.

Enzyme replacement therapy with agalsidase beta in kidney transplant patients with Fabry disease: a pilot study.

BACKGROUND: We sought to assess the safety and efficacy of enzyme replacement therapy (ERT) with recombinant human-alpha-galactosidase A (rh-alpha-Gal A) in kidney transplant recipients with Fabry disease, a previously unstudied population. METHODS: Three male kidney transplant recipients with biochemically, genetically, and histologically confirmed Fabry disease and documented Fabry myocardiopathy received the rh-alpha-Gal A, agalsidase beta, 1 mg/kg of body weight every 2 weeks by intravenous infusion and were monitored biochemically, clinically, and electrocardiographically and echocardiographically for 18 months. RESULTS: Patients showed biochemical, clinical/functional, and morphologic response to ERT. Plasma globotriaosylceramide decreased 23% to 50%. Extremity pain resolved within 2 months in the patient with this manifestation. On echocardiography, left ventricular mass, end diastolic diameter (EDD), and cardiac contractility, shown by ejection fraction (EF), improved in 2 of the 3 patients receiving essentially all planned infusions. EDD and EF remained basically stable, but cardiac morphologic abnormalities progressed in the other patient, who had a 5-month interruption in ERT after the initial month. Mild mitral insufficiency persisted in all patients, as did atrial fibrillation in the affected individual. After a combined total of 116 infusions, no treatment-related adverse event, intolerance, or seroconversion was seen. Renal function remained stable and the immunosuppression regimen unchanged in all patients. CONCLUSION: Our pilot study provides preliminary evidence that ERT with agalsidase beta, 1 mg/kg every 2 weeks, is safe and often effective against extra-renal manifestations in kidney transplant patients with Fabry disease. Studies with longer courses of this and higher doses of ERT are merited in this population.

Interleukin-6 is a stronger predictor of total and cardiovascular mortality than C-reactive protein in haemodialysis patients.

BACKGROUND: Despite the well known association between interleukin-6 (IL-6) and cardiovascular mortality, no study has so far verified whether IL-6 adds prognostic information to that provided by C-reactive protein (CRP). METHODS: A cohort of 218 haemodialysis patients from four different dialytic centres was followed-up retrospectively. Plasma IL-6 and CRP concentrations were determined. Full information on co-morbidities was available in 162 patients. RESULTS: With respect to the lowest quartile (< 3.6 pg/ml for IL-6, and < 2.2 mg/l for CRP), the crude relative risk (RR) of death from all causes of the upper quartile (> 13.9 pg/ml for IL-6, and > 12.8 mg/l for CRP) was 5.20 (95% confidence interval 2.06-13.011) for IL-6 and 3.16 (1.41-7.12) for CRP. When both variables were included, the estimates were 4.10 (1.30-12.96) for IL-6 and 1.29 (0.47-3.57) for CRP. As to continuous variables, the relationship between both variables and mortality tended to level off for the highest values, but became fairly linear after log transformation of the variables. For one unit SD of the log (variable), the RR was 2.09 (1.52-2.88) for IL-6 and 1.66 (1.23-2.24) for CRP. When they were included in the same model, the estimates were 1.90 (1.18-2.82) for IL-6 and 1.16 (0.81-1.66) for CRP. CONCLUSIONS: IL-6 has a stronger predictive value than CRP for cardiovascular mortality and provides independent prognostic information, while conveying most of that provided by CRP.

Effects of calcitriol on the immune system: new possibilities in the treatment of glomerulonephritis.

1. 1,25-Dihydroxyvitamin D3 (1,25(OH)2D3), the hormonal form of vitamin D, is widely appreciated to play a central role in calcium and phosphate homeostasis. However, it is becoming increasingly clear that the sterol also play an important role in the regulation of cellular growth, haematopoietic tissues and the immune system, as well as in the modulation of hormone secretion by several endocrine glands. 2. In the present review, some of the mechanisms by which 1,25(OH)2D3 regulates immune function are highlighted. Moreover, a number of studies on the effects of calcitriol in several experimental animal models of renal disease are reported, suggesting new possibilities in the therapy of glomerulonephritis.

C-reactive protein and interleukin-6 levels are related to renal function in predialytic chronic renal failure.

BACKGROUND: Several studies have provided convincing evidence that in apparently healthy subjects elevated serum levels of plasma C-reactive protein (CRP) are associated with an increased risk of experiencing myocardial infarction and sudden cardiac death. It has been claimed that, in dialytic patients, the hepatic synthesis of this 'acute phase response' plasma protein is primarily induced by the macrophage-derived interleukin 6 (IL-6). Little information is available, however, regarding CRP and IL-6 plasma levels in pre-dialytic renal failure. METHODS: Plasma CRP by a modification of the laser nephelometry technique, IL-6 and serum albumin were determined in 103 chronic pre-dialytic patients (mean age 50 +/- 6.3 years; creatinine clearance (Cr.cl.) 36.3 +/- 23.1 ml/min). RESULTS: CRP was >5 mg/l (normal upper range) in 42% of the global population. CRP and IL-6 were significantly related (r = 0.35, p < 0.0004). CRP and IL-6 were related to renal function (CRP vs. Cr.cl., r = -0.56, p < 0.0001; IL-6 vs. Cr.cl., r = -0.55, p < 0.0001, Spearman correlation coefficient). When patients were divided in tertiles according to renal function, CRP median value resulted 7.9 mg/l (interquartile interval: 5-12) in the first tertile (Cr.cl. <18.5 ml/min), 4.0 mg/l (3-6) in the second tertile (Cr.cl. 18.5-45 ml/min) and 3.2 mg/l (2.7-4.0) in the last tertile (Cr.cl. >45 ml/min) (p < 0.0001). A negative correlation between CRP and S-albumin was also found (r = -0.52, p < 0.0001, Spearman correlation coefficient). CONCLUSIONS: IL-6 and CRP were increased and were inversely related to creatinine clearance in our population of 103 chronic predialytic patients. The possibility of a decreased renal clearance of CRP and/or cytokines as a cause of an activated acute-phase response is discussed. A negative correlation between CRP and S-albumin was found confirming the link between chronic inflammation and malnutrition in chronic renal patients.